Inner surface of a mold to be used in the manufacture of concrete ceilings



FIG. 1 is a bottom plan view of the inner surface of a mold to be usedin the manufacture of concrete ceilings showing my new design;

FIG. 2 is a sectional view taken in the direction of the arrows on line2--2 of FIG. 1.

The ornamental design for the inner surface of a mold to be used in themanufacture of concrete ceilings, as shown.